The imaging of three-dimensional objects so as to obtain high-resolution results is rather difficult. If conventional optical means are used, the image obtained at any instant is in focus only at or near the focal plane of such optical means.
It is known to scan the height of the object, relative the optical instrument, a number of times, resulting in a plurality of images, where only a part of each image is in focus, and where in each such individual image this part delineates a different level of the object or of the height contour of the object.
Another approach is the use of confocal clevis, where the illumination is also focussed at the same height where the image is taken, and thus most not-in-focus information is rejected. In order to obtain the image of the entire object, the entire height must be scanned, which puts severe limits on the type of illumination which can be used. Still another method involves the use of a scanning electron microscope (SEM) which requires cumbersome preparation of most objects and expensive equipment.
With laser profile measurements all non-dimensional information, such as texture, color etc., is lost.
The present invention overcomes to a large extent shortcomings of existing devices and methods of imaging.
The novel system is suitable to reconstruct the image of non planar objects which will not be limited in these ways.